Molecular and Genetic Analysis of COP9, A Regulatory Component Involved in Light-Controlled Development in Arabidopsis

小行星9303029 来自环境的光信号被植物中特定的调节性光感受器感知，并通过未知的机制转导以控制生长和发育。 本研究的长期目标是剖析这些信号转导和整合以调节植物发育的分子机制。 本实验室以光调控拟南芥幼苗发育为模式实验系统。 九COP（组成型光形态发生）基因座，突变时产生黑暗生长的幼苗与光生长的野生型幼苗的形态相似，已被确定。 拟南芥COP 1（组成型光形态发生）基因座，它在光信号传导过程中起着核心作用，并编码一种新的蛋白质，具有推定的DNA结合和G蛋白同源结构域，代表了唯一的光信号成分，除了光敏色素，其特征在于在分子术语。 本实验室的初步研究表明，cop 9突变导致的表型范围与cop 1突变体相同。 因此，COP 9和COP 1可能在相同的信号通路中编码密切相关的调节组分。 本文提出利用一个可利用的T-DNA插入突变等位基因克隆并测序COP 9基因座。 在确定COP 9基因的分子同一性之后，将开发用于分子分析的适当探针（DNA和抗体），并将产生COP 9启动子-GUS转基因植物以分析COP 9基因的表达模式。 有了这些工具，它将使我们能够在分子水平上确定1）野生型COP 9基因产物如何耦合光信号和幼苗发育，以及2）COP 1和COP 9基因之间的关系。 此外，COP 9和其他光形态发生基因座在光调控幼苗发育过程中的调控层次将进行分析。 这些研究的完成不仅将确定将光信号与幼苗发育联系起来的关键调控成分的性质，而且还将为COP 9与其他光形态发生基因的关系提供线索。 ***

9303029 Deng Light signals from the environment are perceived by specific regulatory photoreceptors in plants and transduced by unknown mechanisms to control growth and development. The long term goal of this research is to dissect the molecular mechanisms by which such signals are transduced and integrated to modulate plant development. The light-regulated seedling development of Arabidopsis thaliana has been used as a model experimental system in my laboratory. Nine COP (constitutive photomorphogenic) loci, which when mutated produce dark-grown seedlings with a morphology resembling that of light-grown wild-type seedlings, have been identified. The Arabidopsis COP1 (constitutive photomorphogenic) locus, which plays a central role in the light signaling process and encodes a novel protein with putative DNA-binding and G-protein homology domains, represents the only light signaling component besides phytochrome that has been characterized in a molecular term. The preliminary studies in my laboratory indicate that the cop9 mutation results in the same range of phenotype as the cop1 mutants. Therefore COP9 and COP1 may encode closely related regulatory components in the same signaling pathway. It is proposed here to clone and sequence the COP9 locus, by using an available T-DNA insertional mutant allele. After determining the molecular identity of the COP9 gene, appropriate probes (DNA and antibodies) will be developed for the molecular analysis and COP9 promoter-GUS transgenic plants will be generated for analyzing expression pattern of the COP9 gene. With these tools available, it will enable us to determine at the molecular level 1) how the wild-type COP9 gene product couples light signals and seedling development, and 2) the relationship between the COP1 and COP9 genes. Furthermore, the regulatory hierarchy of COP9 and other identified photomorphogenic loci during light-regulated seedling development will be analyzed. %%% Accomplishment of these studies will not only ascertain the nature of a critical regulatory component that links light signals to seedling development, but also provide clues as to how the COP9 relates to other photomorphogenic genes. ***